Suddenly lost all bluetooth connectivity on iMac 5K

I had an iPhone, Magic Mouse, keyboard, and Trackpad that all simultaneously lost connectivity. I restarted the mac with no help and then got a USB mouse and keyboard connected to troubleshoot this. I turned the Bluetooth off and back on with no result. I powered down the mouse and trackpad and then turned them back on into discovery mode, with no result

Does this indicate that my 8-month-old Bluetooth receiver has bitten the dust or is there another troubleshooting

After that, boot your iMac, go to the Apple menu, About This Mac. Click "System Report", then go to the Bluetooth tab. That should show you almost a page-full of information about the bluetooth hardware and software.
If, after the resets, that information window shows only "This computer doesn't contain any bluetooth devices", or something similar - your next step is to take advantage of your warranty, and let Apple take care of it.

Does your wifi connection work? I think it's all on the same card. One function can fail, but you might not lose both bluetooth and wifi at the same time.
Anyway, Apple will probably need to fix this for you, if the reset doesn't help.

After that, boot your iMac, go to the Apple menu, About This Mac. Click "System Report", then go to the Bluetooth tab. That should show you almost a page-full of information about the bluetooth hardware and software.
If, after the resets, that information window shows only "This computer doesn't contain any bluetooth devices", or something similar - your next step is to take advantage of your warranty, and let Apple take care of it.

Does your wifi connection work? I think it's all on the same card. One function can fail, but you might not lose both bluetooth and wifi at the same time.
Anyway, Apple will probably need to fix this for you, if the reset doesn't help.

Click to expand...

DeltaMac, Thanks for that speedy and authoritative reply. I mentioned the troubleshooting steps I took before posting the first request for help. After that and before I saw your reply I was preparing to go throught PRAM and SMC resets. However, I thought that I'd proceed from simple to more complex by following the restart first with a power-down and cold boot before trying the resets. That resolved the problem. My System Info now shows a Bluetooth report replete with info, but I didn't see your post until the problem was solved, so I don't know what it showed during the SNAFU.

You also asked about Wi-Fi. I didn't actually get a chance to test that as my iMac is on a wired Ethernet connection. It's the first thing I'll check if this happens again. (Interestingly, my Mac flashed a brief screen message that it had lost connectivity with the Mouse and Keyboard, so the System was able to realize that something was amiss, and I wonder if this message might have been consistent with the iMac's Bluetooth receiver remaining intact during the period of lost connectivity.)

My remaining question is whether this has been reported before, so I can know sooner rather than later if it's just a quirk or if my Bluetooth transmitter/receiver is on the way out.

Your Bluetooth bus is associated with the USB bus.
Were you using any kind of USB device when you lost your Bluetooth connection?
A brief over-current from a flaky USB device (external hard drive, USB hub, etc) can knock the USB bus off-line, until you reboot your Mac.
Or, it could also mean that your Bluetooth card is on its way out. (Or, you may never the problem again) Only time will tell. It's not always apparent at the moment when you lose your bluetooth connection, but take notice of what devices, particularly USB devices (and software) that you might be using at the time. This is so you can attempt to duplicate the issue, if you think it needs service.

Your Bluetooth bus is associated with the USB bus.
Were you using any kind of USB device when you lost your Bluetooth connection?
A brief over-current from a flaky USB device (external hard drive, USB hub, etc) can knock the USB bus off-line, until you reboot your Mac.
Or, it could also mean that your Bluetooth card is on its way out. (Or, you may never the problem again) Only time will tell. It's not always apparent at the moment when you lose your bluetooth connection, but take notice of what devices, particularly USB devices (and software) that you might be using at the time. This is so you can attempt to duplicate the issue, if you think it needs service.

Click to expand...

I had a USB hub plugged in with nothing connected to the hub, a USB external optical drive that was in use (although it's tray was open), and I use a wireless Logitech keyboard that, in fact, works from a USB-connected transmitter. The only one of those things that I used during the outage was the USB-wireless keyboard, and it never stopped working, so the USB bus was probably functional all the way through the period of lost Bluetooth connectivity. That explanation sure would have been nice relative to the possibility that the Bluetooth card is going out.

MacRumors attracts a broad audience
of both consumers and professionals interested in
the latest technologies and products. We also boast an active community focused on
purchasing decisions and technical aspects of the iPhone, iPod, iPad, and Mac platforms.